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Stop Sprawl
Forging Transportation Control Measures to Reduce Driving and Clear the Air

Dr. John Holtzclaw
Chair, Sierra Club Transportation Subcommittee
The Transportation and Air Quality Conformity Conference
27-28 Feb 1995, Hyatt Regency Bellevue, WA

Metropolitan planning organizations (MPO) and air quality management districts (AQMD) are looking to transportation control measures (TCM) for solutions to worsening traffic and troublesome air pollution. TCMs come in many forms, from reducing driving by increasing its cost, to better transit, to trip-shortening land use changes, to employer efforts, to reducing emissions by lowering emission limits or improving traffic flow.

To judge this wealth of options, we must understand why Americans drive so much, if we really do. Table 1 compares VMT/capita for seven developed countries. Americans average nearly four times as much driving as the Japanese do, and about twice that of the most developed European countries. Why do we drive so much more than others with incomes similar to ours?

Table 1

1991 Travel by Personal Vehicles for Selected Countries

Country VMT per Capita
Japan 1,928
France 3,510
Italy 3,532*
Sweden 3,743
United Kingdom 4,139
W. Germany 3,512
United States 6,978
Includes privately owned automobiles and light trucks. *1989

Stacy Davis, Transportation Energy Data Book: 14, Oak Ridge National Laboratory, ORNL-6798, 1994, Tables 1.1 and 1.8
Britannica Book of the Year 1991, p 750

America's cars are on welfare

I want to suggest that there are three major reasons Americans drive more than our peers in Europe and Japan. First, we heavily subsidize auto and truck use. Very credible studies--by Charles Komanoff and Brian Ketcham, by the Natural Resources Defense Council, by the World Resources Institute, by the city of Boulder CO, and even by the Office of Technology Assessment, an arm of Congress--calculate total subsidies of $3.00 to $7.00 per gallon of gas.1 Every time we pump in a $1.25 gallon of gas we also pump in $3 to $7 in subsidies. These studies are summarized in Table 2.

Table 2

America's Autos On Welfare: A Summary of Subsidies

$/gal gas,diesel Annual Tot ($bil)
Ketcham and Komanoff 5.53 730
Litman 7.08 935
MacKenzie, Dower & Chen 3.03 400
Moffet & Miller 2.86 - 5.00 378 - 660
Vorhees 4.78 631
Office of Technology Assessment 3.39 - 6.81 447 - 899
OTA, incl non-monetary personal costs
(primarily own accid. & travel time)
11.17 - 16.11 1,475 - 2,127

Where do these subsidies occur? They include the costs of road repair, policing and motorist protection not paid for by the gas tax; "free" parking; uninsured accidents; noise; vibration damage; pollution damage to human health, crops and structures; global warming; petroleum subsidies; policing the petroleum supply line, or wars in the Mid-East; and congestion. Non-drivers subsidize driving when they pay income, sales, property and other taxes used for parking, roads, health care and fighting wars. They subsidize drivers through health or other costs of pollution, or when goods or services include free parking or higher worker health care. Even when drivers pay some of these subsidies, their costs are not directly related to how much they drive, and so are not incentives to drive less. We could take cars off welfare by charging the full cost of parking, increasing gas taxes, instituting pay-at-the-pump insurance, smog fees and congestion pricing on roads. These smell suspiciously like some widely-proposed TCMs.

Public transit is inadequate and deteriorated

Second, we have allowed our public transit systems to deteriorate and be dismantled. Notable was the conspiracy of auto and tire manufacturers and oil companies, under the guise of National City Lines, to buy up and dismantle public transit lines all over the country.2 But state and local governments also participated in dismantling public transit. Meanwhile we spent trillions of public dollars building interstates and other highways. New roads, and the perception that they will reduce traffic congestion, lure people to locate farther from their jobs and shopping.

Congress' 1991 surface transportation act, Intermodal Surface Transportation Efficiency Act (ISTEA), brought a promise of increased spending flexibility between roads and transit. How is that promise being fulfilled? Metropolitan planning organizations and state departments of transportation nationwide are still directing most funds to the same old road projects--an absence of vision on their parts.

Look at how MPOs could forge transit into effective TCMs. They could develop regional transit visions with regional rail networks--modern heavy or light rail systems joining the major urban centers with each other and with major residential areas. Rail, because it is visible and elegant, attracts more support and riders. People better visualize transit routes when they see its tracks. The route's permanence attracts investment in infill housing and commerce, increasing ridership. Feeding these rail systems would be bus networks. State DOTs could develop high speed rail to connect urban areas. Improved public transit could be a very effective TCM.

Many Communities are unwalkable

Third, we have built communities hostile to pedestrians, bicyclists and transit users. Sprawl, now so common, lengthens distances to destination and to transit. Patronage and revenues decline. Expanding routes to provide service within walking distance raises expenses, so service deteriorates. Pedestrian-oriented cities have much higher levels of transit use.

How can we forge communities accessible by foot, bicycle and transit? There are three simple steps. First, increase the density, especially around transit, to multiply the destinations within reach. Second, locate residences, jobs, markets, restaurants, et al close together. Living in the Russian-Nob Hill-Chinatown-North Beach area of northeast San Francisco, I have over 700 restaurants within one mile, an easy and inviting walk, and probably as many food markets. Many of these are corner or mid-block stores on residential streets. Even in less dense neighborhoods these businesses should be located on major streets in the neighborhoods, not stuck off in shopping centers 5 miles away, accessible only by driving.

Finally, design a friendly pedestrian environment, including an efficient pedestrian street grid not broken by dead ends or split by freeways or drainage ditches. Include wide sidewalks, bus shelters, sidewalk furniture and weather protection, convenient building entrances and safe traffic. These three steps improve accessibility to your destinations and to transit: density, mixed-use and pedestrian-friendly.

Now, these are not surprising revelations. Most of you sense this to be true. You've walked through traditional villages crowded with walkers--carrying out their businesses or just enjoying themselves. The sidewalks were wide and inviting. The stores, restaurants and coffee houses were varied, friendly and eye-catching. A mile walk there seemed like a short trip. You loved it, whether this village was a small town, or Greenwich Village, the Loop, North Beach or Chinatown.

Can we prove pedestrian/transit cities really work?

Do we have proof that pedestrian/transit actually reduce driving? We scientists always want numbers. In a couple studies for the Natural Resources Defense Council (NRDC), I analyzed communities in the San Francisco region which varied from high density northeast San Francisco, where I live, to low density suburbs like San Ramon.3 The second study included communities in Los Angeles, San Diego and Sacramento. I found that high residential density, nearby shopping, good transit and a good walking environment go together. And, alternatively, sprawling suburbs isolate stores into shopping centers, have poor transit service, and often don't even have sidewalks.

I found that residents of the higher density communities do drive substantially less. Comparing the extremes, northeast San Francisco was found to have 32 times higher household density, and 200 times higher local serving job density than San Ramon, while its residents had only about 1/4 the household auto ownership and VMT. Both studies found that, on average, we drive 20 to 30 percent less per capita or per household than residents of an area half as dense. In other words, if you live in a neighborhood with twice the density of your sister's, on average you will drive 20 to 30% less than she and her neighbors. This general relationship of density to auto use was also found in New York, Chicago, Toronto and British cities.

The basic question for planners is--what do we really want to accomplish: moving more vehicles--which planners term mobility, or facilitating people getting to their destinations--which we call accessibility? If you can walk to the market or telecommute to work you have accessibility but no mobility! Aren't we now providing mobility, albeit often congested mobility, to those with cars, and denying it to those who can't afford cars, or are young or old, or who just don't want to drive? Wouldn't TCMs which give accessibility without moving so many cars be effective, and more equitable? There are TCMs that decrease driving and congestion while increasing accessibility.

Employee Trip Reduction Ordinances

But wait, how are air quality agencies and transportation planners attacking excessive driving? With Employee Trip Reduction Ordinances (TRO)! Yeah, ask the employer to solve the problem, even though only one-fourth of trips are work trips, yielding one-third of total VMT. Actually, there is some sense to this requirement, since congestion is worst during commute hours and one goal is to reduce congestion, as well as the extra pollution from stop-and-go traffic. Also, non-driving employees are less likely to make drive-alone trips at noon.

The 1990 Clean Air Act Amendments require Employee Commute Options (ECO) in the twelve most polluted regions of the country. The California Clean Air Act requires air quality agencies in the most polluted air basins to enact local ordinances designed to achieve an Average Vehicle Ridership (AVR) of 1.5 for commute trips. Hence, the South Coast Air Quality Management District's infamous Reg. XV. It requires employers to develop a plan to achieve this at each work site with 100 or more morning commuters. Get this--it doesn't require achieving 1.5, only developing plans and making efforts to achieve it.

Less polluted basins, like the San Francisco area, must enact local ordinances designed to achieve an AVR of 1.4 for commute trips. Like Reg. XV, the Bay Area Air Quality Management District's Reg. 13 only requires preparation and implementation of employer plans. To achieve a regionwide AVR of 1.4, the BAAQMD divided the region into four zones, as shown on Figure 1. Downtown San Francisco has to achieve an AVR of 2.5 by 1999; the rest of San Francisco and downtown Oakland and Berkeley must achieve 1.5; the rest of Alameda county, along with San Mateo, Santa Clara and Contra Costa must achieve 1.35; while the northern counties of Marin, Sonoma, Napa and Solano only have to meet 1.3. Even then, some suburban employers came to the air district complaining "we chose to locate our sites out in the boonies where land is cheap, but there is no transit nor nearby housing so let us off the hook! Lower our goals even more." That's probably not exactly the way they phrased it, but that's what I heard.

As you can see, the bulk of the effort is loaded on downtown San Francisco. Already one county meets its 1999 goal, so its employers don't have to prepare TRO plans. Which county? San Francisco! This demonstrates the effectiveness of higher densities, good local shopping, pedestrian-oriented streets, good transit, and limited downtown parking!

TCM effectiveness

Let's look at the whole spectrum of TCMs. For discussion, I'll classify them as market-based, land use, pedestrian/bicycle/transit, traffic improvements and telephone-based, as shown in Table 3.

We have predictions of TCM effectiveness for four major urban regions: San Francisco, Los Angeles, Washington DC and New York City. We usually measure effectiveness by VMT reductions. Since cold engines (cold starts) emit more pollutants than hot ones, vehicle trips (VT) are also important. However, VMT is the universally reported measure of effectiveness. These predictions are based on measured or estimated responses of travelers to increases or decreases in travel costs or time.

These predictions include immediate responses to changed travel conditions and secondary impacts--as when the reduced traffic following a gas tax increase lures others to drive. But these predictions do not adequately model the longer-term reductions resulting from densification, or people moving or changing employment locations to take advantage of improved transit. Or the synergism among some TCMs, yielding even more VMT reductions than indicated for each one acting alone. For instance, mixed-use infill development, pedestrian and transit improvements, and barriers to parking might give greater reductions than simply adding the effects of each acting alone.

While the predictions vary between regions, general conclusions can be drawn. Sharp reductions in VMT can be achieved by market-based TCMs, land use changes or achieved pedestrian/bicycle/transit improvements. The greatest short-term reductions in VMT are by the strongest market-based measures. But is it reasonable to talk about a $2 gasoline tax?

Figure 2 shows gasoline taxes and prices in the U.S., Canada, many European countries and Japan. $2 gas taxes are common elsewhere.

A combination of land use and pedestrian/bicycle/transit improvements can give substantial reductions. Traffic improvements can actually increase VMT, however, as driving increases to take advantage of reduced congestion. Telecommuting might reduce rush hour commutes, but may free up employees for more mid-day trips.

In addition to these TCMs, efforts to clean up auto emissions by tightening emissions limits on new cars and inspection & maintenance of operating vehicles are sometimes thought of as TCMs with statewide or nationwide implementation.

Testing an integrated package of TCMs

How would you test the effectiveness of a package of TCMs? We analysts say "Pay us to model it on the computer." The San Francisco bay area's MPO, the Metropolitan Transportation Commission (MTC), put their analysts to work doing that. They tested an integrated package of TCMs for the Regional Alliance For Transit (RAFT) -- a transit and environmental coalition. RAFT defined a pedestrian- and transit-oriented projection for MTC to analyze as a part of the development of the 20-year Regional Transportation Plan (RTP).

RAFT specified a year 2010 transportation system which eliminated nearly all of MTC's 500 new highway lane-miles, and put the savings into cost-effective public transit. It stressed rail improvements in the urban corridors, including CalTrain from San Jose to San Francisco's downtown Transbay Terminal, light rail in San Francisco and Santa Clara counties, heavy rail on existing tracks to link Santa Clara light rail to East Bay BART and on to Livermore, Sacramento and San Joaquin county, and commuter rail in Marin and Sonoma counties. RAFT also included electric trolley-buses in the East Bay urban corridor between Hayward, Oakland and Richmond, and express buses on I-80 and I-680. Having improved CalTrain service to San Francisco Airport, RAFT eliminated the parallel, more expensive, BART extension. RAFT converted some freeway lanes to bus/carpool lanes.

RAFT included only one market-based measure: parking cash-out, whereby non-driving employees receive the cash value of their unused "free" parking space. This was the only market measure that could be implemented immediately, without changes in state law or a vote of the electorate. California law allows county congestion management agencies to mandate such parking cash-out.

RAFT assumed the same total regional population and job growth as MTC, but clustered the growth of households and employment after 1995 around transit stations. It saved some 200 square miles of forests, grasslands and farmlands that MTC's alternative would have developed for residences, commerce, industry and local streets. By developing in areas mostly supplied with infrastructure -- schools, public facilities, streets and utilities, the region could save the $25 billion cost of new facilities.5

MTC's models predict that by 2010 RAFT's alternative would reduce VMT 6% below MTC's alternative, saving the average family 1,148 miles of travel annually,6 worth $379, using FHWA estimates of auto costs.7 RAFT saves 350,000 gallons of fuel daily and cuts mobile source particulate emissions 10.2%, carbon monoxide 3.8%, reactive organic gases 4.9% and nitrogen oxides 5.0%. Further, RAFT cuts congestion by 7%.

RAFT boosts transit passengers regionwide by 24% over MTC's alternative, with Muni Metro up 29%, Caltrain 167%, Santa Clara light rail 76%, East Bay heavy rail (Amtrak) 152%, and AC Transit 39%. RAFT boosts BART patronage 15% above MTC's RTP even though it eliminated BART's proposed extension from Colma to the San Francisco Airport.

You can see how effective this package of TCMs would be. And this package doesn't include the many market-based measures that local authorities now lack the authority to implement. The potential to utilize TCMs to improve our lives and our air quality is there, given political courage and leadership.

TCM Recommendations

Adding these studies up, what conclusions can we draw? Make sure that your region considers and evaluates a full spectrum of potential TCMs. Forge an integrated package of TCMs that is effective in reducing VMT. That package should include:

  • strong market measures to reduce or eliminate subsidies to driving and increase the per-mile and per-trip cost of driving;
  • strict limits on highway capacity increases, with perhaps some strategic reductions in capacity;
  • improvements in transit, especially rail, transit coordination, and pedestrian and bicycle access to transit;
  • zoning, financial incentives and public education to encourage higher density, mixed-use development near transit stations and in transit corridors; and
  • pedestrian and bicycle improvements to increase the pleasure or walking and riding in neighborhoods.

Moreover, be very cautious about TCMs that would change signal timing, intersection reconfiguration or other changes to speed traffic. While smoother traffic pollutes less, it can drive VMT up as drivers move farther from work to take advantage of decreased commute times, etc. This could swamp the smoother flow effects. And the faster traffic threatens pedestrians and bicyclists.

Transportation Control Measures, writ large, can be a very effective tool for improving our urban areas, decreasing traffic and improving air quality. You can help your community to use them effectively.

A colleague of mine urged me to address another reason we drive so much--our "car culture". Americans are felt to be one with their cars, inseparable. A person without a car is not really a person. Mention cars and we picture ourselves tooling along an empty country road, as depicted in TV ads. This image obscures reality. The normal experiences of most Americans is stuck in traffic. As auto ownership and VMT expand this congestion will get worse. Yet, the $4.5 billion auto manufacturers annually pump into ads keeps this idealized image vibrant and autos seemingly essential to our quality of life. How do we address this problem? Will exposing us to the magnitude of our subsidies to cars, and the harm cars do to the environment, our cities and our accessibility smudge the glossy image of cars?

Table 3
Predicted Effectiveness of Transportation Control Measures

Vehicle Miles Traveled
$2/gal gasoline tax -10.3%
$1/gal gasoline tax -4.5%
8 cent/mile smog fee -8.3%
Smog based registration fee -0.4% -0.4% -1.4%
$3/day employee parking -1.5% -1.5%
Employee parking cash-out -3% -1.9%
$2/day vanpool/carpool incentives -0.3%
1 cent/minute non-work parking -4.9% -3.5% -2.1% -3.9%
15 cent/mile average congestion pricing -5% `
Automated congestion-priced toll lanes -2% -4.5%
Increased bridge tolls -2.4% -1.2%
50 cent/gal pay-at-the-pump insurance -1.9% -1.9%
Employee trip reduction ordinance -2.5% -1.3% -0.4%
Mixed-use infill, growth management -2.7% -2.7%
Zoning changes for density near transit -0.1%
Pedestrian/bicycle access improvements -.1% -1.3%
traffic calming, ped/bike improvements -2.7% -3.4%
Prohibiting thru traffic in selected centers -.5% -1.9%
Expanded transit, ped/bike access -2.1%

Grieg Harvey, TCM Task Force, Metropolitan Transportation Commission, Oakland CA 1989
Michael Cameron, Transportation Efficiency: Tackling Southern California's Air Pollution and Congestion,Environmental Defense Fund, Oakland CA, 1991, Table 3.
Michael Replogle, Transportation Management Strategies For the Washington DC Region, Environmental Defense Fund, Washington DC, August 1993, p 7 (year 2000)
Tri-State Transportation Campaign, Citizens Action Plan, A 21st Century Transportation System, New York City, April 1994, p 66 (year 2007).

1.Charles Komanoff and Brian Ketcham, Win-Win Transportation: A No-Losers Approach to Financing Transport in New York City and the Region, 9 July 1992 draft.

John Moffet and Peter Miller, The Price of Mobility: Uncovering the Hidden Costs of Transportation, Natural Resources Defense Council, San Francisco, October 1993.

James MacKenzie, Rover Dower and Donald Chen, The Going Rate: What It Really Costs To Drive, World Resources Institute, Washington DC, June 1992.

Michael Vorhees, The True Costs of the Automobile to Society, City of Boulder, CO, January 1992.

Office of Technology Assessment, Saving Energy in U.S. Transportation, Washington DC, OTA-ETI-589, 1994.

2. James Howard Kunstler, The Geography of Nowhere, Simon and Schuster, New York, 1993, pp 91 & 211.

3. John Holtzclaw, Explaining Urban Density and Transit Impacts on Auto Use, Natural Resources Defense Council, 15 January 1991, in California Energy Commission Docket No. 89-CR-90.

John Holtzclaw, Using Residential Patterns and Transit To Decrease Auto Dependence and Costs, Natural Resources Defense Council, San Francisco, and California Home Energy Efficiency Rating Systems, Costa Mesa, CA, June 1994.

4. Greig Harvey, TCM Task Force, Metropolitan Transportation Commission, Oakland CA, 1989.

Michael Cameron, Transportation Efficiency: Tackling Southern California's Air Pollution and Congestion, Environmental Defense Fund, Oakland CA, 1991, Table 3.

Michael Replogle, Transportation Management Strategies For the Washington DC Region, Environmental Defense Fund, Washington DC, August 1993, p 7 (year 2000).

Tri-State Transportation Campaign, Citizens Action Plan, A 21st Century Transportation System, New York City, April 1994, p 66 (year 2007).

5. Using per acre mixed suburban infrastructure costs, in 1994 dollars, from Real Estate Research Corporation, The Costs of Sprawl: Detailed Cost Analysis, U.S. G.P.O. Stock Number 4111-00021, Council on Environmental Quality, Department of Housing and Urban Development, and the Environmental Protection Agency, Washington DC, April 1974.

6. Dahms, L. "Memorandum to Work Program Committee: Regional Alliance for Transit Proposal for RTP Track 1." Metropolitan Transportation Commission, 101 Eight St, Oakland CA 94607, 13 May 1994.

7. Federal Highway Administration. Cost of Owning & Operating Automobiles, Vans & Light Trucks: 1991. U.S. Department of Transportation, Washington D.C., Table 4.